Technical Abstract:
We have developed an improved Agrobacterium-mediated protocol in plum (Prunus domestica L.) through the addition of 2,4-D to the regeneration media. This method has increased the regeneration efficiency of independent transgenic plants up to 10 fold over previous reports. DNA blot analysis of putative transgenic shoots revealed transformation efficiencies of up to 42% with an average of 25% over all trials. The timing in each step of the regeneration/transformation process has been optimized for producing self-rooted transgenic plants in approximately six months. The high transformation rates coupled with the rapid plant establishment methodology make it possible to utilize plum transformation, not only for the introduction of agronomically useful genes into this species, but as model plant for functional genomics studies in Prunus spp., Rosaceaous species, and woody plants, in general. In addition, transformation with genes that promote early flowering, such as leafy, apetala1 or ptft1, are being explored to reduce the time to flowering, enabling rapid evaluation of flower and fruit specific gene functions.